Hydraulic friction device for



July 7, 1931. J GI 1,813,351 HYDRAULIC FRICTION DEVICE FOR KNITTING MACHINES Fild Dec. 4, 1930 s Sheets-Sheet 1 ATTORNEY 1&133511 J. GIFT July 7 1931.

HYDRAULIC FRICTION DEVICE FOR KNITTING MACHINES Filed Dec. 4, 1950 3 Sheets-Sheet 2 ATTORNEY July 7, 1931. J. GIFT 1,813,351

HYDRAULIC FRICTION DEVICE FOR KNITTING MACHINES Filed Dec. 4, 1930 5 Sheets-Sheet 3 Patented July 7, 1931 I JOHN GIFT, OF SOUTH TEMPLE, PENNSYLVANIA HYDRAULIC FRICTION DEVICE FOR KNITTING MACHINES Application filed December 4, 1930. Serial No. 500,107.

My present invention relates to certain new and useful improvements in the driving mechanism for thread carriers in full fashion knitting machines and has for an object the provision of means to be used in lieu of the present friction devices whereby a smooth, more rapid, more positive and more uniform operation may be obtained than by the use of those friction devices now commonly employed.

In machines at present in general use the arm which connects the driving (reciprocating) friction rod or bar with the driven thread carrier rod is mounted on the friction rod r'otatably and is operatively coupled to that rod by a device commonly known as a friction device. This device usually consists of leather rod-engaging elements which are intendedto grip the rod with sufficient rezo taining friction to cause the rod and the arm and consequently the thread carrying rod to reciprocate in unison until the movement of the thread carrier rod is arrested by the stroke delineating stops located at either end of the pathof travel of the thread carrier rod. The distance between a pair of stops varies with the width of the stocking or other article being knit. Due to the slippage of the friction device on the friction rod as the stops come into action, the leather or other friction material used soon becomes worn and unless frequently replaced and frequently adjusted soonbecomes uncertain in its action with the result that im- '35 perfect articles are knit. It is therefore anformly and effectively without the necessity of constant supervision and/or adjustment of parts.

Further, it is an object to provide a mechanism for the purposes stated in which the yieldable connection between the friction rod' or bar and the arm that connects it to the thread carrier rod is practically free from wear.

Further, it is an object. to provide a mechanism for the purposes described which will operate without producing a rebound.

Further, it is an object to provide a mechanism for the purposes described which operates hydraulically which is self-contained and has provisions for the release of its holding function when desired as when making tension adjustments.

Further, it is an object to provide a mechanism of the character stated wherein the supply of liquid used maybe and is automatically kept free from trapped air in the working parts which might tend to cause improper operation.

Other objects will inpart be obvious and in part) be pointed out hereinafter.

To the attainment of the aforesaid objects and ends, the invention still further resides in the novel details of construction, combination and arrangement of parts all of which will be first fully described in the following detailed description, then be particularly pointed out in the appended claims, reference being had to the accompanying drawings, in which Figure 1 is a diagrammatic view illustrating the use of my invention.

Figure 2 is an enlarged detail vertical longitudinal section of my invention with the parts in the neutral or central position.

Figure 3 is a view similar to Eigure2 showing the position of the parts when the motionof the sliding shaft has been arrested, as when'a stop has arrested the movement of the thread carrier rod. 85

Figure 4 is a longitudinal section showing how the tension of the device may be adjusted.

Figure 5 is a cross section on the line 5-5 of Figure 2.

Figure 6- is a cross section on the line 6-6 of Figure 2.

Figure 7 is a detail perspective view of the ball valve seat and its cage separated.

Figure Sis a detail view showing the holding springs and notches of the sliding shaft and valve carrier.

Figure 9 is .a cross section on the line 9-9, of Figure 8.

- In the drawings in which like numerals J of reference indicate like parts in all of the figures, 1 represents the friction rod or bar which is reciprocated by a mechanism comprising a rocking lever 2, a cam actuated rod 4, one end of which is pivoted to the lever 2, and the other end is pivoted to a rod hanger 5, the rod 4 being actuated by the cam 3 of the knitting machine. 6 designates the thread carrier rod and 7 the stops which are engaged by the ends of the rod 6 at either extreme of its reciprocation. The rod 6 has motion imparted to it from the bar 1 throu h the medium of the arm 55 as will hereinafter more clearly appear.

8 designates a cylinder supporting body or yoke member that is suitably secured to the bar 1 and is provided with split bearings 9 for a sliding shaft 10. The sliding shaft 10 is of tubular construction and has its ends located within a pair of main cylinders 11, the latter having mounting flanges 12 b which they are secured to the yoke mem er 8, suitable washers 13 being interposed. The main cylinders are secured to the yoke by suitable screws 14 as shown. The washers 13 are preferably felt washers and exert a wiping action on the sliding shaft 10 to keep the shaft clean where it moves through its bearings and to prevent excess oil creeping past the bearings.

The outer ends of the main cylinders 11 are internally threaded and closed by screw plugs 15 which may be secured against unscrewing by lock screws 16. These plugs 15 have squared sockets 17 on their inner faces for the reception of the squared reduced ends of the valve carrier 20, the purpose of which will later appear.

The sliding shaft 10 is of slightly less diameter than the internal diameters of the main cylinders 11 so that there will be a slight clearance between the surfaces of the same, except that at the extreme outer ends of the sliding shaft 10 the shaft is provided with flan es 18 that have bearing on the inner sur aces of the main cylinders as pistons.

20 represents a valve carrier of tubular construction having a passageway through the same from end t3 end, the carrier 20 being threaded as at 21 into the end of the shaft 10 and having a shoulder 22 which carries one or more latching springs 58 to cooperate with the latching notches 19 on the end of the piston portion 18 of the shaft 10 and prevent an accidental unscrewing of the valve carrier within the end of the sliding shaft 10.

The valve carrierhas an extension 23 threaded at 24 to receive a cupped washer 26 of leather or other suitable material, a disk washer 27 and a nut 28 as best shown in Figure 2 of the drawings.

The valve carrier has its central passage enlarged to provide a main valve seat 29 and to receive in the enlargement 30 the main valve 31, which valve is also of tubular form and has longitudinal grooves 32 in its periphery constituting oil passes. The inner end of the main valve 31 is internally threaded at 33 to receive the by-pass valve seat element 34 with which the by-pass valve 35 cooperates, the valve 35 preferably being a ball valve and being held to its seat by a light spring 38 contained in the guard 37 of the valve cage, the ring 36 of which is clamped in place by the element 34' when screwed home.

The main valve 31 has a tension spring recess 39 for the reception of the tension spring 40, which spring engages an abutment 41 that is secured within the tubular sliding shaft 10 at a suitable distance from the valve carrier 20 and serves to normally seat the main valve 31. The abutment 41 has a suitable bearing for the by-pass valve unseating push rod 42. It also has oil passes 44. Suitable devices 43, preferably screws, are provided to retain the abutment 41 in place. It will, of course, be understood that the mechanism just described is dgplicated at each end of the sliding shaft 1 About midway of the ends of the shaft 10 there is mounted a by-pass Valve releasing shaft 45 having arms 46 which are connected with the push rods 42 by connecting rods 47, the shaft 45 passing through a stufiing box bearing 48 and carrying a manually operated lever 49 at its outer end.

Projecting from the shaft 10 is a guide pin 50 which works in a longitudinal slot 51 in the yoke 8 and prevents swivelling of the shaft 10 in its bearings 9.

52 are oil cups disposed at the outer ends of the main 0 linders 11, and 53 designates air vents in t e cylinders 11 adjacent their inner ends.

The arm 55 which connects the sliding shaft 10 with the thread carrier rod 6 has a bifurcated bearing part 54 mounted on the shaft 10 and straddling a collar 56 secured to that shaft, the arm 55 when thrown over into engagement with the socket 58 on the thread carrier rod 6 serves to couple that rod operatively to the friction rod or bar 1.

The entire shaft 10 and the ends of the cylinders 11 beyond the ends of the shaft 10 are filled with oil or other suitable incompressible liquid. The filling may be effected through the cups 52, it being understood that the cups 52 have closed so as to hold the necessary pressure within the cylinders and sliding shaft.

Now assume that the hollow shaft 10, the ends of the cylinder 11 beyond the ends of the shaft, the valve carriers 20, and the main valves 31 and oil cups 52 to be filled with the incompressible fluid, and assume that the shaft has been turned to withdraw the push rods 42 from the valve 35 so that the valves may be free to act, and assume further that the arm has been swung into engagement with the socket of the rod 6. The bar 1 is reciprocated by the cam 23 and its operating, mechanism 42 so as always to make strokes of constant length, carrying with it the yoke 8 and the parts carried thereby. As soon, however, as the rod 6 engages a stop 7 its movement will be arrested. Let us assume that the bar 1 is moving from right to left in Figure 3, and the left hand stop is engaged by the rod 6 to bring it to rest before the bar 1 has completed its stroke toward the left. The right hand cylinder continuing its movement will force the oil ahead of the piston 18, 26 at the right hand end of the shaft 10 to How toward the left, thereby moving the main valve 31 off its seat 29 and permitting the oil to flow through the grooves 32 in the periphery and openings 41 toward the left hand end of the shaft 10 where the oil pressure will unseat the by-pass valve 35 at the left hand end and permit the oil to flow through the by-pass into the enlarging space between the left hand end of the shaft 10 and the left hand end of the left hand cylinder 11.

As soon as the movement of the bar has ceased, the valves 31 and 35 will immediately become seated and on the return stroke of the bar 1 the sliding shaft 10 will then move in unison with it. It should be understood that the stroke of the bar 1 is always greater than the stroke of the shaft 10 in order to insure a full stroke of the shaft 10 at the maximum stroke position regardless of the relative positions of the shaft 10 and cylinders 11.

Should air get into the cylinders and shaft it will'be displaced by the oil contained in the reservoir or cups 52. Any loss of oil by leakage past moving parts will be compensated for by oil from the cups 52, thereby insuring a full supply of oil at all times.

While I have referred to the use of oil in my device (and oil is preferred) other suitable non-compressible liquids may be used if desired.

\Vhen it. is desired to alter the tension of the device, i. e., to alter the effective action of the springs 39, the shaft 45 is turned to cause the push rods 42 to unseat the bypass valves 35, then the hollow shaft 10 is grasped by hand and pushed in the direction of the end whose spring is thereby adjusted. This brings the squared parts 25 and 17 into engagement. Then by releasing the guide pin 50, the shaft 10 can be turned on its axis which causes the valve carrier 20 to be screwed into orout of the shaft more or less as may be desired to increase or diminish the tension of the spring 39. Having made the adjustment the shaft 10 is moved axially in the opposite direction to disengage the parts 25 and 17 and the shaft 45 is turned to withdraw the push rods 42 so that the valves 35 may again seat. The pin 50 is returned to its guide slot 51 and the apparatus is ready for further operation.

Changes in the details of construction and arrangement of partsmay readily be made by those skilled in the art without departingfrom the spirit of the invention as defined by the appended claims, and while my device has especially been designed to take the place of friction drive now employed in knitting machines, its use may be of broader application and I do not desire to be confined to the specific use described.

It will also be observed my device also acts as a shock absorber to prevent rebound when the thread carrier. bar engages the stops.

What I claim is:

1. In a hydraulic friction device, a body, means to effect a stroke of constant length of said body, a shaft slidably carried by said body, and hydraulic means operatively coupling said body and said shaft together, said means having provisions to permit sliding movement to occur between said shaft and said body when a predetermined resistance is encountered by said shaft.

2. In knitting machines, a thread carrier rod, a reciprocating bar, means to reciprocate said bar, an arm joining said rod and bar combined with a hydraulic friction device for yieldably connecting said arm with said bar to cause the two to move in unison at times and to permit the arrest of said thread carrier rod without arresting the movement of said bar at other times.

3. In a hydraulic friction device the combination with a body, means for reciprocating said body, and a sliding shaft carried by said body, a hydraulic coupling between said body and shaft to cause said shaft normally to move with said body and to permit said body to slide with respect to said xshaft when said shaft engages an obstruction.

4. In a hydraulic friction device the combination with a body, means for reciprocating said body, and a sliding shaft car-' ried by said body, of a hydraulic coupling between said body and shaft to cause said shaft normally to move with said body and to permit said body to slide with respect to said shaft when said shaft engages an obstruction, said hydraulic coupling including a cylinder carried by said body and receiving one end of said shaft as a piston, said shaft having a liquid chamber, an incompressible liquid in said liquid chamber, a main valve in said one end opening inwardly to pass liquid from said cylinder through said valve into said shaft, a spring to seat said valve, and a by-pass valve within said main valve to open outwardly, and a spring for seating said by-pass valve.

5. In a hydraulic friction device, the combination with a body, means for reciprocating said body, and a sliding shaft carried by said body, of a hydraulic coupling between said body and shaft to cause said shaft normally to. move with said body and to permit said body to slide with respect to sai shaft when said shaft engages an obstruction, said hydraulic coupling including a cylinder carried by said body and receiving one end of said shaft asiapiston, said shaft having a liquid chamber, an incompressible liquid in said liquid chamber, a main valve in said one end opening inwardly to pass liquid from said cylinder through said valve into said shaft, a spring to seat said valve, a by-pass valve within said main valve to open outwardly, and a spring for seating said by-pass valve, said main valve including a valve carrier threaded into said shaft and having a squared projecting end, said cylinder having a squared soclfet to receive said projecting end for the purposes described.

6. In a hydraulic friction device, the combination with a body, means for reciprocating said body, and a sliding shaft carried by said body, of a hydraulic coupling between said body and shaft to cause said shaft normally to move with said body and to permit said body to slide with respect to said shaft when said shaft engages an obstruction, said hydraulic coupling including a cylinder carried by said body and receiving one end of said shaft as a' piston, said shaft having a liquid chamber, an incompressible liquid in said liquid chamber, a main valve in said one end opening inwardly to pass liquid from said cylinder through said valve into said shaft, a spring to seat said valve, a by-pass valve within said main valve to open outwardly, a spring for seating said by-pass valve, said main valve including a valve carrier threaded into said shaft and having a squared projecting end, said cylinder having a squared socket to receive said projecting end, and operator controlled means to unseat said by-pass valve.

7. In a hydraulic friction device, a body, a pair of opposite coaxially extending cylinders carried by said body, a sliding shaft carried by said body with its ends located in their respective cylinders, means to reciprocate'said body, stops to arrest the stroke of said shaft, a hydraulic coupling means between said cylinders and said shaft to cause the same to move in unison, said hydraulic coupling means including provisions to permit said shaft to be arrested by said stops without arresting the movement of said body.

8. In a hydraulic friction device, a body, a pair of opposite coaxially extending cylinders carried by said body, a sliding shaft carried by said body with its ends located in their respective cylinders, means to reciprocate said body, stops to arrest the stroke of said shaft, a hydraulic coupling means between said cylinders and said shaft to cause the same to move in unison, said hydraulic coupling means including provisions to permit said shaft to be arrested by said stops without arresting the movement of said body, said means comprising a main valve and a by-pass valve, and pressure applying means normally to seat said main valve, said main and by-pass valves acting in opposite directions.

9. In a hydraulic friction device, a body, a pair of opposite coaxially extending-cylinders carried by said body, a sliding shaft carried by said body with its ends located in their respective cylinders, means to reci rocate said body, stops to arrest the stro e of said shaft, a hydraulic coupling means between said cylinders and said shaft to cause the same to move in unison, said hydraulic coupling means including provisions to permit said shaft to be arrested by said stops without arresting the movement of said body, said means comprising a main valve and a by-pass valve, and pressure applying means normally to seat said main valve, said main and bypass valves acting in opposite directions, and means to adjust the force of said pressure applying means.

10. In a hydraulic friction device, a body, a pair of opposite coaxi ally extending cylinders carried by said body, a sliding shaft carried by said body with its ends located in their respective cylinders, means to reciprocate said body, stops to arrest the stroke of said shaft, a hydraulic coupling means between said cylinders and said shaft to cause the same to move in unison, said hydraulic coupling means including provisions to permit said shaft to be arrested by said stops withoutarresting the movement of said body, said means comprising a main valveand a by-pass valve, a tension spring continuously tending to seat said main valve, said main valve and said bypass valve operating in opposite directions, and means to adjust the tension of said spring.

11. In a hydraulic friction device, a body, a pair of opposite coaxially extending cylinders carried by said body, a sliding shaft carried by said body with its ends located in their respective cylinders, means to reciprocate said body, stops to arrest the stroke of said shaft, a hydraulic coupling means between said cylinders and said shaft to cause the same to move in unison, said hydraulic coupling means including provisions to permit said shaft to be arrested by said stops without arresting the movement rier adapted to be engaged by moving said shaft to the limit of its movement into said cylinder, whereby turning said shaft on its axis will screw in or outsaid carrier to increase or decrease the compression of said spring according to the direction in which said shaft is turned".

12. In a hydraulic friction device, a body, a pair of opposite coaxially extending cylinders carried by said body, a sliding shaft carried by said body with its ends located in their respective cylinders, means to reciprocate said body, stops to arrest the stroke of said shaft, a hydraulic coupling means between said cylinders and said shaft to cause the same to move in unison, said hydraulic coupling means including provisions to permit said shaft to be arrested by said stops without arresting the movement of said body, said means comprising a main valve and a by-pass valve, a tension spring continuously tending to seat said main valve, said main valve and said by-pass valve op erating in opposite directions, and means to adjust the tension of said spring, said adjusting means including a valve carrier threaded into said shaft, an abutment carried by the shaft for one end of said spring, the other. end of said spring engaging said main valve, and a mechanical coupling means between said cylinder and valve carrier adapted to be engaged by moving said shaft to'the limit of its movement into said cylinder, whereby turning said shaft on its axis will screw in or out said carrier to increase or decrease the compression of said spring according to the direction in which said shaft is turned, and means for opening mechanically said by-pass when it is desired to bring said mechanical coupling into action.

13. In knitting machines, the combination with. a thread carrier rod and a reciprocating bar, of a connection between the same to cause the rod and bar to reciprocate .together, said connection comprising a hydraulic friction device.

14. In knitting machines, the combination with a thread carrier rod and a reciprocating bar, of a connection between the same to cause the rod and bar to reciprocate to gether, said connection comprising a hydraulic friction device, said hydraulic friction device having rovisions to permitsaid rod to be arrested without arresting the movement of said bar.

15. In knitting machines, the combination with a thread carrier rod and a reci rocating bar, of aconnection between t e same to cause the rod and bar to reciprocate together, said connection comprising a hydraulic friction device, said hydraulic friction device comprisin ayoke havin shaft bearings, a hollow sllaft axially sli able in said bearings, a cylinder fitted over each end of said shaft and secured to said yoke, each cylinder having its outer end closed, a valve carrier fitted in each end of I said shaft, each .valve carrier including a piston dividing its cylinder into two compartments, said valve carriers each having a passageway through the same, an incompressible liquid contained in said hollow shaft and in the outermost end chambers of the cylinders, a main valve in each valve carrier for normally closing its passageway, a by-pass valve in each main valve, the bypass valves operating in directions opposite to those of their respective main valves, and means continuously tending to seat said valves.

.16. In knitting machines, the combination with a thread carrier rod and a reciprocating bar, of a connection between the same to cause the rod and bar to reciprocate together, said connection comprising a hydraulic friction device, said h draulic friction device comprising a yo e havin shaft bearings, a hollow shaft axially sli able in said bearings, a cylinder fitted over each end of said shaft and secured to said yoke, each cylinder having its outer end closed, a valve carrier fitted in each end of said shaft, each valve carrier including a piston dividing its cylinder into two compartments, said valve carriers each having a passageway through the same, an incompressible liquid ing bar, of a connection between the same I to cause the rod and bar to reciprocate together, said connection comprismg a hydraulic friction device, friction device comprising a yoke having shaft bearings, a hollow shaft axially slidable in said bearings, a cylinder fitted over each end of said shaft and secured to said y k ea h y e. aving its o terend said hydraulic j closed, a valve carrier fitted in each end of said shaft, each valve carrier including a piston dividing its cylinder into two compartments, said valve carriers each having a passageway through the same, an incompressible liquid contained in the outermost end chambers of the cylinders and in said hollow shaft, a main valve in each valve carrier for normally closing its passageway, a by-pass valve in each main valve, the by-pass valves operating in directions opposite to those of their respective main valves, means contin= uously tending to seat said valves, means to adjust at will the effective force of the main valve seating means, and manually operable means to hold said by-pass valves unseated at will.

18. In knitting machines, the combination with a thread carrier rod and a reciprocating bar, of a connection between the same to cause the rod and bar to reciprocate together, said connection comprising a hydraulic friction device, said hydraulic friction device comprising a yoke having shaft bearings, a hollow shaft axially slidable in said bearings, a cylinder fitted over each end of said shaft and secured to said yoke, each cylinder having its outer end closed, a valve carrier fitted in each end of said shaft, each valve carrier including a piston dividing its cylinder into two compartments, said valve carriers each having a passageway through the same, an incompressible liquid contained in said hollow piston and in the outermost end chambers of the cylinders, a main valve in each valve carrier for normally closing its passageway, a by-pass valve in each main valve, the bypass valves operating in directions opposite to those of their respective main valves, means continuously tending to seat said valves, means to adjust at will the effective force of the main valve seating means, and manually operable means to hold said bypass valves unseated at will, said manually operable means comprising a rocker shaft journalled in bearings in said hollow shaft, said rocker shaft having arms, push rods to engage said by-pass valves, and links connecting said push rods to said arms.

19. In knitting machines, the combination with a thread carrier rod and a reciprocating bar, of a connection between the same to cause the rod and bar to reciprocate together, said connection comprising a hydraulic friction device, saidhydraulic friction device comprising a yoke having shaft bearings, a hollow shaft axially slidable in said bearings, a cylinder fitted over each end of said shaft and secured to said yoke, each cylinder having its outer end closed, a valve carrier fitted in each end of said shaft, each valve carrier including a piston dividin its cylinder into two compartments, said valve carriers each having a passageway through the same, an incompressible liquid contained in said hollow shaft and in the outermost end chambers of the cylinders, a main valve in each valve carrier for normally closing its passageway, a by-pass valve in each main valve, the by-pass valves operating in directions opposite to those of their respective main valves, means continuously tending to seat said valves, and means holding said hollow shaft against rotating about its axis 20. In knitting machines, the combination with a thread carrier rod and a reci rocating bar, of a connection between t e same to cause the rod and bar to reciprocate together, said connection comprising a hydraulic friction device, said hydraulic friction device comprisin a yoke having shaft bearings, a hollow s aft axially slidable in said bearings, a cylinder fitted over each end of said shaft and secured to said yoke, each cylinder having its outer end closed. a valve carrier fitted in each end of said shaft, each valve carrier including a piston dividing its cylinder into two compartments, said valve carriers each having a passageway through the same, an incompressible liquid contained in said hollow shaft and in the outermost end chambers of the cylinders, a main valve in each valve carrier for normally closing its passage way, a by-pass valve in each main valve,

the by-pass valves operating in directions opposite to those of their respective main valves, means continuously tending to seat said valves, means to adjust at will the effective force of the main valve seating means, and manually operable means to hold said by-pass valves unseated at will, said manually operable means comprising a rock shaft journalled in bearings in said hollow shaft, said rock shaft having arms, push rods to engage said by-pass valves, and links connecting said push rods to said arms, and means holding said hollow shaft against rotating about its axis.

21. In knitting machines, the combination with a thread. carrier rod and a reciprocating bar, of a combined hydraulic shock absorber and friction unit including means for yieldably connecting said rod and bar.

22. In knitting machines, the combination with a thread carrier rod and a reciprocating bar, and a connection between said rod and bar whereby the rod is reciprocated through the movement of the bar, of a combined h draulic shock absorber and fric-' tion unit cooperating with the aforesaid parts for the purpose described.

- JOHN GIFT. 

